181 lines
6.5 KiB
Markdown
181 lines
6.5 KiB
Markdown
# llhttp
|
|
[](https://github.com/nodejs/llhttp/actions?query=workflow%3ACI)
|
|
|
|
Port of [http_parser][0] to [llparse][1].
|
|
|
|
## Why?
|
|
|
|
Let's face it, [http_parser][0] is practically unmaintainable. Even
|
|
introduction of a single new method results in a significant code churn.
|
|
|
|
This project aims to:
|
|
|
|
* Make it maintainable
|
|
* Verifiable
|
|
* Improving benchmarks where possible
|
|
|
|
More details in [Fedor Indutny's talk at JSConf EU 2019](https://youtu.be/x3k_5Mi66sY)
|
|
|
|
## How?
|
|
|
|
Over time, different approaches for improving [http_parser][0]'s code base
|
|
were tried. However, all of them failed due to resulting significant performance
|
|
degradation.
|
|
|
|
This project is a port of [http_parser][0] to TypeScript. [llparse][1] is used
|
|
to generate the output C source file, which could be compiled and
|
|
linked with the embedder's program (like [Node.js][7]).
|
|
|
|
## Performance
|
|
|
|
So far llhttp outperforms http_parser:
|
|
|
|
| | input size | bandwidth | reqs/sec | time |
|
|
|:----------------|-----------:|-------------:|-----------:|--------:|
|
|
| **llhttp** | 8192.00 mb | 1777.24 mb/s | 3583799.39 req/sec | 4.61 s |
|
|
| **http_parser** | 8192.00 mb | 694.66 mb/s | 1406180.33 req/sec | 11.79 s |
|
|
|
|
llhttp is faster by approximately **156%**.
|
|
|
|
## Maintenance
|
|
|
|
llhttp project has about 1400 lines of TypeScript code describing the parser
|
|
itself and around 450 lines of C code and headers providing the helper methods.
|
|
The whole [http_parser][0] is implemented in approximately 2500 lines of C, and
|
|
436 lines of headers.
|
|
|
|
All optimizations and multi-character matching in llhttp are generated
|
|
automatically, and thus doesn't add any extra maintenance cost. On the contrary,
|
|
most of http_parser's code is hand-optimized and unrolled. Instead describing
|
|
"how" it should parse the HTTP requests/responses, a maintainer should
|
|
implement the new features in [http_parser][0] cautiously, considering
|
|
possible performance degradation and manually optimizing the new code.
|
|
|
|
## Verification
|
|
|
|
The state machine graph is encoded explicitly in llhttp. The [llparse][1]
|
|
automatically checks the graph for absence of loops and correct reporting of the
|
|
input ranges (spans) like header names and values. In the future, additional
|
|
checks could be performed to get even stricter verification of the llhttp.
|
|
|
|
## Usage
|
|
|
|
```C
|
|
#include "llhttp.h"
|
|
|
|
llhttp_t parser;
|
|
llhttp_settings_t settings;
|
|
|
|
/* Initialize user callbacks and settings */
|
|
llhttp_settings_init(&settings);
|
|
|
|
/* Set user callback */
|
|
settings.on_message_complete = handle_on_message_complete;
|
|
|
|
/* Initialize the parser in HTTP_BOTH mode, meaning that it will select between
|
|
* HTTP_REQUEST and HTTP_RESPONSE parsing automatically while reading the first
|
|
* input.
|
|
*/
|
|
llhttp_init(&parser, HTTP_BOTH, &settings);
|
|
|
|
/* Parse request! */
|
|
const char* request = "GET / HTTP/1.1\r\n\r\n";
|
|
int request_len = strlen(request);
|
|
|
|
enum llhttp_errno err = llhttp_execute(&parser, request, request_len);
|
|
if (err == HPE_OK) {
|
|
/* Successfully parsed! */
|
|
} else {
|
|
fprintf(stderr, "Parse error: %s %s\n", llhttp_errno_name(err),
|
|
parser.reason);
|
|
}
|
|
```
|
|
For more information on API usage, please refer to [src/native/api.h](https://github.com/nodejs/llhttp/blob/main/src/native/api.h).
|
|
|
|
## Build Instructions
|
|
|
|
Make sure you have [Node.js](https://nodejs.org/), npm and npx installed. Then under project directory run:
|
|
|
|
```sh
|
|
npm install
|
|
make
|
|
```
|
|
|
|
---
|
|
|
|
### Bindings to other languages
|
|
|
|
* Python: [pallas/pyllhttp][8]
|
|
* Ruby: [metabahn/llhttp][9]
|
|
|
|
### Using with CMake
|
|
|
|
If you want to use this library in a CMake project you can use the snippet below.
|
|
|
|
```
|
|
FetchContent_Declare(llhttp
|
|
URL "https://github.com/nodejs/llhttp/releases/download/v6.0.5/llhttp-release-v6.0.5.tar.gz") # Using version 6.0.5
|
|
|
|
FetchContent_MakeAvailable(llhttp)
|
|
|
|
target_link_libraries(${EXAMPLE_PROJECT_NAME} ${PROJECT_LIBRARIES} llhttp ${PROJECT_NAME})
|
|
```
|
|
|
|
## Building on Windows
|
|
|
|
### Installation
|
|
|
|
* `choco install git`
|
|
* `choco install node`
|
|
* `choco install llvm` (or install the `C++ Clang tools for Windows` optional package from the Visual Studio 2019 installer)
|
|
* `choco install make` (or if you have MinGW, it comes bundled)
|
|
|
|
1. Ensure that `Clang` and `make` are in your system path.
|
|
2. Using Git Bash, clone the repo to your preferred location.
|
|
3. Cd into the cloned directory and run `npm install`
|
|
5. Run `make`
|
|
6. Your `repo/build` directory should now have `libllhttp.a` and `libllhttp.so` static and dynamic libraries.
|
|
7. When building your executable, you can link to these libraries. Make sure to set the build folder as an include path when building so you can reference the declarations in `repo/build/llhttp.h`.
|
|
|
|
### A simple example on linking with the library:
|
|
|
|
Assuming you have an executable `main.cpp` in your current working directory, you would run: `clang++ -Os -g3 -Wall -Wextra -Wno-unused-parameter -I/path/to/llhttp/build main.cpp /path/to/llhttp/build/libllhttp.a -o main.exe`.
|
|
|
|
If you are getting `unresolved external symbol` linker errors you are likely attempting to build `llhttp.c` without linking it with object files from `api.c` and `http.c`.
|
|
|
|
#### LICENSE
|
|
|
|
This software is licensed under the MIT License.
|
|
|
|
Copyright Fedor Indutny, 2018.
|
|
|
|
Permission is hereby granted, free of charge, to any person obtaining a
|
|
copy of this software and associated documentation files (the
|
|
"Software"), to deal in the Software without restriction, including
|
|
without limitation the rights to use, copy, modify, merge, publish,
|
|
distribute, sublicense, and/or sell copies of the Software, and to permit
|
|
persons to whom the Software is furnished to do so, subject to the
|
|
following conditions:
|
|
|
|
The above copyright notice and this permission notice shall be included
|
|
in all copies or substantial portions of the Software.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
|
|
NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
|
|
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
|
|
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
|
USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
[0]: https://github.com/nodejs/http-parser
|
|
[1]: https://github.com/nodejs/llparse
|
|
[2]: https://en.wikipedia.org/wiki/Register_allocation#Spilling
|
|
[3]: https://en.wikipedia.org/wiki/Tail_call
|
|
[4]: https://llvm.org/docs/LangRef.html
|
|
[5]: https://llvm.org/docs/LangRef.html#call-instruction
|
|
[6]: https://clang.llvm.org/
|
|
[7]: https://github.com/nodejs/node
|
|
[8]: https://github.com/pallas/pyllhttp
|
|
[9]: https://github.com/metabahn/llhttp
|